1. Field of the Invention
The present invention relates to systems for selectively dispensing liquid from a container, and more particularly, to a system having a pump assembly selectively pressuring the liquid to be dispensed and a retractable-extendible wand-shut off assembly, wherein differences in manufacturing tolerances of the components do not limit functionality of the system.
2. Description of Related Art
Dispensing systems for the spray application of pesticides, insecticides, plant and grass nutrients, for lawn and garden applications have been available for many years.
These systems can include telescoping conduits to allow the operator to be spaced from discharge of the liquid. However, such telescoping conduits require an extensive series of seals and sealing surfaces. The number of sealing surfaces in conjunction with manufacturing tolerances of components and the desired price point typically result in leakage. In addition, a change in length of the telescoping conduit changes the available volume and thus can result in increased liquid pressure acting on the components of the system, which can lead to failure or unintended discharge.
U.S. Pat. No. 5,553,750 discloses a system including a trigger sprayer having cylindrical handle connected to a container closure, and a flexible tubing stored within the container during periods of non-use wherein the tubing is drawn from the container during the spraying operation. In a further configuration in U.S. Pat. No. 5,553,750, the tubing is coiled and stored within a receptacle located within the container during periods of non-use.
However, storage and uncoiling of the tubing is cumbersome and awkward, as the coil may stick or snag as the coils pulled out of the container. In addition, the trigger sprayer and handle are at a fixed size that remain connected to the container during periods of non-use, such as shipping and storage. This requires additional storage space and shelf space, thereby creating inefficiencies.
U.S. Pat. No. 5,469,993 provides a trigger sprayer with a handle that is stored within a recess provided in a sidewall of the container, wherein the recess is sized and shaped for releasably engaging the sprayer handle. The tubing connecting the container to the trigger sprayer is coiled and stored within a hollow trigger sprayer handle. In use, the handle is removed from the container recess, and the connector plugged into a spout on the container.
However, the container and trigger handle must be specially molded to provide the removable mounting. The available molding process for obtaining the required tolerances is costly and uneconomical. In addition, as the operator employs the trigger sprayer, the material is discharged proximal to the hand of the operator.
Further, such trigger operated sprayers require the pump mechanism be disposed within the handheld trigger, thereby substantially limiting the capacity of the pump mechanism. Therefore, a significant number of trigger cycles are required to dispense a given volume of liquid. This relatively high number of trigger cycles can lead to operator fatigue, or if in a professional setting, carpal tunnel syndrome.
Thus, the need exists for a fluid dispensing system which can reduce exposure of the operator to the material being applied, while providing a flexible conduit between a grip and a container. The need also exists for a dispensing system that can be readily reconfigured between a storage (or shelf) configuration and an operable configuration, without further pressurizing the system. The need further exists for a dispensing system that can incorporate components of different manufacturing tolerances (associated with different manufacturing processes), without sacrificing performance, or increasing costs.